Vat dyestuffs of the benzanthrone series and a process of making same



Patented Sept. 1, 1931 UNITED-STATES PATENT OFFICE PAUL NAWIASKY, onLUDWIGSHAFEN-ON-THERHINE, AND EDUABD HOLZAPFEL AND or'ro BR-AUNSDORF, orHOCHST-GN-THE-MAIN, GERMANY, ASSIGNORS T GENERAL 7 ANILINE wonxs, mo, ornew YORK, 1v. A CORPORATION VAT D YESTUFFS'OETHE BE NZANTHRONE SERIESAND A PROCESS OF MAKING SAME No Drawing. Application filed October 10,1925, Serial No. 61,775, and in Germany October 20, 1924.

. Our present invention relates to the preparation of vat dyestuifs ofthe benzanthrone series.

l/Ve have found that benzanthronylsulfides and other thio-ethers of the,benzanthrone, for instance alkylor aryl-benzanthronyl thioethers andalso their derivatives are converted into vat. dyestuffs by treatingthem with alkali metal hydroxides.

The benzanthronyl-compounds above mentioned may be, for instance,obtained by'the actionof a sulphur halide upona benzanthrone or byacting on halogen benzanthrones or nitro-benzanthrones or-nitro-haloge'n benzanthrones withsulphur or certain sulphur compounds.In the caseof halogen deriva-' tives of benzanthrone, the reaction iscarried out withan inorganic sulphide particularly [alkali metalsulphide or with aryl-mercapn tans or benzanthrone mercaptans, While inthe case of nit-rosbenzanthrones or nitro-halogen-benzanthrones sulphuritself or benzanthrone-mercaptans arev most suitably employed. As is'thecase with the unsubstituted Bz-l-thio-ethers of the benzanthrone, thecondensation of the various substituted thioethers of benzanthrone withalkaline condensing agents takes place in a more uniform and easiermanner than in the hitherto known processes. I

The following examples serve to illustrate our invention, the partsbeing by weight: 1. parts of caustic potashare mixed with 4-5 parts ofethyl alcohol and into this mixture is introduced at about 135 C. onepart of B21, Bzl-benzanthronysulphide and the molten mass is then heatedto 140 C. until the reaction is complete. The dyestuif, after beingisolated in the usual manner 4b forms a dark violet powder which,without necessitating any further purification, dissolves inconcentrated sulfuric acid to a pure green solution. The dyestufl issoluble, but only with great difficulty, in nitro benzene to 5 areddish-violet solution showing a bright red fluorescence. The dyestufl'has proved to be free from sulfur. It gives. with hydrosulfite abluish-violet vat dyeing a violet tint with a considerably redder huethan the isoviolanthrone describedin U. S. Patent No. 906,367 issuedDecember 8, 1908 and it ma therefore, beregarded as a substantial ypurer isoviolanthrone of the formula:

l 2. Into a fusion of alcoholic potassium hydroxide, obtained by heating80 parts of potassium hydroxide and 80 parts of ethyl alcohol to C. anddistilling off the excess of alcohol, are introduced at 135140" C. 20partsof Bz-l-thiocresyl benzanthrone produced for instance by heatingBz-l-chloro benzanthrone with the calculated quantity ofpara-thio-cresol and: potassium hydroxide in alcoholic solution, and theresulting molten mass is stirred for one hour at PLO- C.

Thereupon the mass is'diluted with water and into this suspension air ispassed until the dyestuif dissolved in form of its hydro compound iswholly precipitated; the product is then 1.

ofpotassium hydroxide and parts of a1- r We claim: 1. As a new product,6.6'-diamino-isodicohol are, introduced at about 140 C. 7 parts of Bz-lbenzanthronyl mercaptanmethyl-ether (melting point 152-154 C.)benzanthrone of the followng'formula: and the whole is then stirred forabout one 7 hour at the same temperature. The reaction I 7% mixture,after being worked up in the usual manner yields isodibenzanthroneequaling as regards purity the product prepared according to thepreceding examples. 7 v I 7 4L. lOpartS of Bz2.Bz2-;dim-ethoxy-Bzl, 7 V'1': Bzl-benzanthronyl-sulfide obtained by sub mitting Bz2 methoxy Bzlhalogen benzanthrone-to retaction with sodium poly-sulfide, areintroduced at 130-140 G. into a fusion of 15 parts of caustic potash and40 parts of SC ethyl alcohol and the reaction mixture is stirred :at thesaid temperature until the formation of the Bz2-Bz2 dimethoxyisodibenzanithroneofthe iorniulas 2O s 35 o Y NH -25 i being a dark blueviolet powder soluble in concentrated sulfuric acid with a greenco'lor,yielding a blue vat from which cotton is dyed violet-blue. p I

2. The process which comprises melting a 2.30'Bz-l-Bz-l-benzanthronylsulfide with an allra li metal hydroxide in thepresence of an is complete. The dyestufl 1S lsolabed m the a iphaticIDOHbtOlDlC alcohol of low inolecu usual manner and forms a bluish blackpowder' which dissolves in concentrated sulfuric acid with a'recldish'vio'let color and gives with hydrosulfite a blue vat dyeingcotton 'bluetints.

5. Into a fusion, heated to 135-140 (1, of parts of caustic potash and80 parts of ethyl'zalcohol are introduced, while stirring, 20 p'arts of66--dianiino-'Bz-1-Bz-1'-ben-zanliar Weight.

3. The process which comprises heating a fide with caustic potash in thepresence of ethyl alcohol forabout one hour to a temperature of about135l l'0 C.

V thronyl si-il-fide ,(produced'Ebjy the action of sodiumadisulphide'upon 6-nitro-Bz -bromobenzanthrone at a temperature varyingfrom In testimony whiereoi, we alfix our signaturesj i PAUL NAWIASKY.

130 to 150 (3.); The mixture is kept for l q E 1 w 7 about-one hourlat'135-140 C. and the dye- -v is'isola'ted as usual. It is 6;6-'diramino-7 -c l. o isodibenzanthrone of the formula:

v 55 v 12c I "It constitutesa bluish violet powder which dissolvesconcentrated sulfuric acid to a 1 green solution and gives withwhydrosullite a 65 blue 'vat dyeing cotton violet-blue tints.

